public class Solution {
    public int takeAttendance(int[] records) {
        int left = 0,right = records.length - 1;
        while(left < right) {
            int mid = left + (right - left) / 2;
            if(records[mid] == mid) left = mid + 1;
            else right = mid;
        }
        return records[left] == left ? left + 1 : left;
    }

    public static void main(String[] args) {
        Solution solution = new Solution();
        int[] records = {0, 1, 2, 3, 4, 5, 6, 8};
        System.out.println(solution.takeAttendance(records));
    }
}
